code: def call(self, step):
      mindsdb_database_name = "mindsdb"
  
      predictor_name = step.predictor.parts[-1]
      dn = self.session.datahub.get(mindsdb_database_name)
      columns = dn.get_table_columns(predictor_name)
  
      data = ResultSet()
      for column_name in columns:
          data.add_column(
              Column(
                  name=column_name,
                  table_name=predictor_name,
                  database=mindsdb_database_name,
              )
          )
      return data
  
file_path: mindsdb/mindsdb/api/executor/sql_query/steps/prepare_steps.py
imports: from mindsdb_sql.parser.ast import Identifier, Constant, Select, Star
  from mindsdb_sql.planner.steps import GetPredictorColumns, GetTableColumns
  from mindsdb.api.executor.sql_query.result_set import ResultSet, Column
  from .base import BaseStepCall
label_desc: Use image node_id 1 for calling the GetPredictorColumnsCall obj's underlying member method code with example usage: obj.call(step) and returns: data